Abstract
Spontaneously evolving Turing structures in the chlorine dioxide-iodine-malonic acid reaction-diffusion system typically exhibit many defects that break the symmetry of the pattern. Periodic spatial forcing interacts with the Turing structures and modifies the pattern symmetry and wavelength. We investigate the role of the amplitude and wavelength of spatial periodic forcing on the hexagonal pattern of Turing structures. Experimental results and numerical simulations reveal that forcing at wavelengths slightly larger than the natural wavelength of the pattern is most effective in removing defects and producing ordered symmetric hexagonal patterns.